From 1bc5ad168f441f6f8bfd944288a5f7b4963ac1f6 Mon Sep 17 00:00:00 2001 From: Marcel Holtmann Date: Tue, 17 Dec 2013 03:21:25 -0800 Subject: Bluetooth: Fix HCI User Channel permission check in hci_sock_sendmsg The HCI User Channel is an admin operation which enforces CAP_NET_ADMIN when binding the socket. Problem now is that it then requires also CAP_NET_RAW when calling into hci_sock_sendmsg. This is not intended and just an oversight since general HCI sockets (which do not require special permission to bind) and HCI User Channel share the same code path here. Remove the extra CAP_NET_RAW check for HCI User Channel write operation since the permission check has already been enforced when binding the socket. This also makes it possible to open HCI User Channel from a privileged process and then hand the file descriptor to an unprivilged process. Signed-off-by: Marcel Holtmann Tested-by: Samuel Ortiz Signed-off-by: Johan Hedberg --- net/bluetooth/hci_sock.c | 26 ++++++++++++++++---------- 1 file changed, 16 insertions(+), 10 deletions(-) (limited to 'net') diff --git a/net/bluetooth/hci_sock.c b/net/bluetooth/hci_sock.c index 71f0be17308..73bf644c7c7 100644 --- a/net/bluetooth/hci_sock.c +++ b/net/bluetooth/hci_sock.c @@ -942,8 +942,22 @@ static int hci_sock_sendmsg(struct kiocb *iocb, struct socket *sock, bt_cb(skb)->pkt_type = *((unsigned char *) skb->data); skb_pull(skb, 1); - if (hci_pi(sk)->channel == HCI_CHANNEL_RAW && - bt_cb(skb)->pkt_type == HCI_COMMAND_PKT) { + if (hci_pi(sk)->channel == HCI_CHANNEL_USER) { + /* No permission check is needed for user channel + * since that gets enforced when binding the socket. + * + * However check that the packet type is valid. + */ + if (bt_cb(skb)->pkt_type != HCI_COMMAND_PKT && + bt_cb(skb)->pkt_type != HCI_ACLDATA_PKT && + bt_cb(skb)->pkt_type != HCI_SCODATA_PKT) { + err = -EINVAL; + goto drop; + } + + skb_queue_tail(&hdev->raw_q, skb); + queue_work(hdev->workqueue, &hdev->tx_work); + } else if (bt_cb(skb)->pkt_type == HCI_COMMAND_PKT) { u16 opcode = get_unaligned_le16(skb->data); u16 ogf = hci_opcode_ogf(opcode); u16 ocf = hci_opcode_ocf(opcode); @@ -974,14 +988,6 @@ static int hci_sock_sendmsg(struct kiocb *iocb, struct socket *sock, goto drop; } - if (hci_pi(sk)->channel == HCI_CHANNEL_USER && - bt_cb(skb)->pkt_type != HCI_COMMAND_PKT && - bt_cb(skb)->pkt_type != HCI_ACLDATA_PKT && - bt_cb(skb)->pkt_type != HCI_SCODATA_PKT) { - err = -EINVAL; - goto drop; - } - skb_queue_tail(&hdev->raw_q, skb); queue_work(hdev->workqueue, &hdev->tx_work); } -- cgit v1.2.3-18-g5258